Sheet separating and feeding mechanism



Feb. 20, 1951 R. T. CHATTERTON 2,541,985

SHEET SEPARATING AND FEEDING MECHANISM Filed Dec. 19, 1946 2Sheets-Sheet l INVENTOR wrm BY Z ATTORNEYS Feb. 20, 1951 R. T.CHATTERTON 2,541,985

SHEET SEPARATING AND FEEDING MECHANISM Filed Dec. 19, 1946 2Sheets-Sheet 2 INVENTOR Maid/1w; BY

ZZZ #1910? 4. ATTORN EYS Patented Feb. 20, 1951 SHEET SEPARATING ANDFEEDING MECHANISM Robert T. Chatterton, Wappingers Falls, N. Y., as-

signor to American Can Company, New York, N. Y., a corporation of NewJersey Application December 19, 1946, Serial N 0. 717,307

'8 Claims; (61. 271-44) The present invention relates to a feedingmechanism for flat sheet metal blanks or sheets and has particularreference to devices for magnetically fanning out the blanks at thebottom of a stack to separate them preparatory to feeding them from thebottom of the stack.

An object of the invention is the provision of a feeding mechanism forfiat sheet metal blanks wherein the blanks at the bottom of such a stackare magnetically fanned out and separatedto facilitate their being fedfrom the bottom of the stack so that replenishment of the supply ofblanks will be at the top of the stack without interfering with thefeeding action, thereby insuring continuous feeding of the blanks fromthe stack.

Another object is the provision of such a feeding mechanism wherein theblanks at the bottom of the stack are supported independently of theother blanks in the stack and along one edge only thus leaving theopposite edge free and unsupported to facilitate the magnetic fanningout and separation of the blanks preparatory to being fed from thebottom of the stack.

Another object is the provision of such a feeding mechanism wherein themagnet means are utilized for fanning out the blanks at the bottom ofthe stack to separatethem preparatory to ieedingthem from the bottom ofthe stack, the magnet means being arranged to retain the blanks in theirfanned out relation when the mechanism for any reason temporarily ceasesoperation.

Another object is the provision of such a feeding mechanism which issimple in construction and compact in form so that it may be readilyincorporated in existing machines, such as for example can body makingmachines, printing or lithographing machines, lithograph ovens and manyother machines for performing operations on the fed blanks.

Numerous other objects and advantages of the invention will be apparentas it is better understood from the following description, which, takenin connection with the accompanying drawings, discloses a preferredembodiment thereof. I

Referring to the drawings:

Figure 1 is a top plan view of a feeding mech anism embodying theinstant invention, with parts broken away and showing blanks inposition;

Fig. 2 is a longitudinal sectional view taken substantially along theline 2-2 in Fig. 1, with parts broken away and with blanks shown in sideelevation; and

Fig. 3 is a transverse sectional view taken substantially along the line3-3 in Fig. 2, with parts broken away. I

Asa preferred embodiment of the instant invention the drawingsillustrate principal parts of a mechanism for feeding sheet metal canbody blanks A made preferably of tin plate or the like material, from astack of such blanks' for advancement through a can body making machine.

The stack of blanks A is retained in a magazine B located at the feed-inend of the machine, the stack being disposed in an inclined position tosupport the load of the major portion of the stack and to facilitateloading or replenishment of the su ply of blanks at the top of thestack. This inclined stack is supported on a pair oi spaced and parallelinclined support elements or guides H which are bolted to'brackets I 2secured to the main frame of the machine. ,The feeding or rear edges ofthe blanks in the stack engage against these guides. The opposite edgesof --the blanks near the .bottom of the stack engage against a pair ofspaced and parallel, non-mag netic vertical support elements or guidesl5 which are mounted indirectly on the machine frame. Adjacent their endedges the blanks areretained in stacked formation by inclined side,guides l6 secured to the machine frame.

The blanks in the stack are fed individually from the bottom of thestack by conventional devices which first draw the lowermost blank downinto a bowed condition and then slide the bowed blank forward from thebottom of the magazine. Such a conventional feeding device is disclosedin Fig. 9 of United States Patent 1,770,041, issued July 8, 1930, to J.F. Peters, on Roll Bodymaker.

Drawing down of the blank is effected prefer ably by a suction cup I8which is disposed below the magazine and which is carried on the innerend of a pivoted arm I9. The arm is rocked, to lower and raise the cup,in any suitable manner as by a link 2: actuated n timeflwith'thje otherparts of the machine. Support rails 22 disposed below the magazine holdthe blank adjacent its ends during this bowing action. I Q.

Advancement of the bowed-down blank is et fected preferably bydepressible feed dogs 23 carriedin a pair of spaced and parallel feedbars 24 which operate in slideways formed in the machine frame. Thesefeed bars are reciprocated in unison in any suitable manner, as forexample by a link 25 actuated in timewith the other movin parts of themachine. 1

Provision is made for magnetically separating the blanks A at the bottomof the stack to create a space between them so that the blanks will be 3prevented from sticking together while being fed from the magazine. Thisprevents feeding doubles" through the machine.

Separation of the blanks A at the bottom of the stack takes place alongtheir inner or forward edges only, while the outer or rear edges of theblanks are supported on a bottom support or short foot member 3! formedon the lower ends of each of the inclined guides ll. These foot membersextend inwardly from a curved edge section 32 of the guides H, thecurved edge Sections defining a notch or recess 33 in the guides.

Directly opposite the foot member not the inclined guides H, thevertical support guides I! are formed with inwardly inclined or undercutedge or track sections 36 for the unsupported inner edges of the blanksA at the bottom of the magazine. Between the vertical support guides land adjacent the inclined edge sections 36 there is acontinuouslyenergized electro-magnet 31 which is connected by wires 38. 39 to anysuit able source of electric energy. This magnet is formed with ahardened steel core 4| which extends through the vertical support guidesl5 and a pair of hardened steelpole pieces 42 which are carried on theouter ends of the core adjacent the guides l5. -'Ihe magnet sets up amagnetic field adjacent the non-magnetic track sections 38 of the guidesIS.

The inner faces of the pole pieces 42 are flat and are disposed at anacute angle to and in spaced relation to the path of travel ofthe blanksA moving along the inclined tracks 36, the upper ends of the pole piecesbeing spaced a greater distance from the tracks 36 than the lower endsas best shown in Fig. 2. Thus a decreasing air gap is provided betweenthe edges of the passing blanks A and the pole pieces.

The air gap between the blank edge and the magnet is effective as areluctance gap for each individual blank and the flux density in thespace will be less than that within the blanks; The effector this is toprevent adjacent blanks approaching too closely together. However, theflux density in the blanks varies in accordancewith the distance betweenthe edge of the individual blanks and the angularly disposed face of themagnet pole pieces, the greater flux density being in the blanks nearestthe magnet. This therefore provides a definite separation of eachindividual blank while in the separation zone. and causes the bottomblank to be positioned accurately for removal by the suction cup 13 (seeFig. 2).

In operation the rear edges of the blanks A, at the bottom of the stacksupported in the magazine, ride down along the curved edge sections 32of the inclined support guides II and enter the notches 33 where theycome to rest in a supported condition on the foot members 3|. Thismovement of the rear edges of the blanks causes the forward edges of theblanks to ride down along the inner edges of the vertical support guidesl5 and thus fall unsupported into the space defined by the inclined edgeor track sections 36of these vertical guides. The falling blank pivotson its supported rear edge using the notches 33 as a pivot or fulcrum.

As the forward edges of th blanks pass into the space adjacent the tracksections 36 of the vertical non-magnetic support guides l5, they enterthe magnetic field of the magnet 31. This entrance of the unsupportedblank edges into the magnet field is accompanied by a magnetic fluxwhich pulls the blanks into contact with the tracks 36 and which passesinto the blanks and thereby separates and causes them to fan out. asbest shown in Fig. 1. The rear edges of the blanks are still supportedon the foot members 3| of the rear inclined guides I I.

The magnetic field retains the blanks at the bottom of the.stack in thisseparated fanned-out condition, while the suction cup 18 bows down thelowermost separated blank in the stack and the feed dogs 23 remove andadvance the blank as hereinbefore explained. In this manner theseparation of the blanks at the bottom of the stack in no way interfereswith replenishment of the supply of blanks at the top of the stack. Inother words new blanks are supplied without in any way interfering withremoval of the blanks from the bottom of the stack. This insurescontinuous feeding of the blanks individually from the bottom of thestack without the possibility of feeding a "double.

In case of temporary failure of electric energy for the magnet 31, thehardened steel core and pole pieces retain suilicient magnetism tomaimtain the magnetic field and thus retain the blanks at the bottom ofthe stack in their separated fanned-out relation so that immediatecollapse of the stack is prevented.

- construction andarrangement of the parts withblanks along thesupported side resting on each other with the opposite side unsupported,and magnet means disposed opposite said support means and on theunsupported side of said stack for fanning out the unsupported side ofsaid supported blanks at the bottom of the stack to separate the blankspreparatory to feeding them individually from the bottom of thestack.

2. In a feeding mechanism for flat sheet metal blanks, the combinationof a magazine for maintaining the blanks in stacked formation, bottomsupport means located on one side of said magazine for supporting saidstack adjacent its bottom and with the blanks resting on and supportingone another adjacent said support means leaving the other sideunsupported, and magnet means arranged beyond the unsupported blankedges on the opposite side of said magazine for fanning out thesupported blanks at the bottom of the magazine on the side adjacent saidmagnet means to separate the blanks preparatory to feeding them fromsaid magazine.

3. In a feeding mechanism for flat sheet metal blanks, the combinationof a magazine having oppositely disposed guides for maintaining blanksin stacked formation between them, said guides on one side of saidmagazine having bottom support means for supporting a plurality of theblanks at the bottom of the stack along one edge, said guides on theopposite side of the magazine being undercut for the free passage of theadjacent unsupported edges of the blanks at the bottom of the stack, andmagnet means arranged adjacent the undercut guides for fanning out theunsuping them from said magazine.

4. In a feeding mechanism for flat sheet metal blanks, the combinationof a magazine having oppositely disposed guides for maintaining blanksin stacked formation between them, said guides on one side of saidmagazine being disposed in an inclined position to facilitate loading ofthe blanks into the magazine and for supporting the load of the majorportion of the stack and having bottom support means for supporting aplurality of the blanks at the bottom of the stack along one edge, saidguides on the opposite side of the magazine being undercut for the freepassage of the adjacent unsupported edges of the blanks at the bottom ofthe stack, and magnet means arranged adjacent the undercut guides forfanning out the unsupported edges of the blanks at the bottom of thestack to separate the blanks preparatory to feeding them from saidmagazine.

5. In a feeding mechanism for flat sheet metal blanks, the combinationof support means for supporting a stack of blanks adjacent its bottomand on one side by supporting each blank on the next adjacent blank onthat side with the opposite side unsupported, magnet means disposedopposite said support means on the "opposite side of the stack andadjacent the unsupported edges for fanning out the supported blanks atthe bottom of the stack to separate the blanks, holding means locatedbelow the bottom of the stack and out of the influence of saidmagnetmeans, means for drawing the lowermost separated blank down below thebottom of the stack and onto said holding means, and feeding means forengaging said drawn-down blank and for feeding it along said holdingmeans and beneath said magnet means.

6. In a feeding mechanism for sheet metal blanks, the combination of amagazine having oppositely disposed guides for maintaining blankstherebetween in stacked formation, a said guide on one side of saidmagazine being disposed in an inclined position for supporting saidstack, said inclined guide having a notch in its guiding surface merginginto a foot member located at the bottom of said guide, said foot membersupporting a predetermined quantity of sheets on one side of the stack,a said guide on the opposite side of the magazine having a guidingsurface.

for engaging the sheets as they pass into said notch said guide surfacemerging into an inclined undercut wall for guiding the blanks at thebottom of the stack supported on said foot, and magnet means locatedadjacent said undercut surface for fanning out the unsupported edges ofthe blanks on said footto separate the blanks preparatory to feedingthem from the bottom of the stack.

7. In a feeding mechanism for flat sheet metal blanks, the combinationof means for holding a stack of blanks in a predetermined position bysupporting one side on a surface extending beneath the stack with theother side of the blanks unsupported, non-magnetic guides havinginclined guiding faces located adjacent the unsupported side of theblanks for aligning the adJacent blank edges, and magnet means locatedon the same side of the stack as said guides, said magnet means havingpole pieces disposed in spaced relation to one another and having facesset back from and at an acute angle to the guiding faces of said guidesfor providing an air gap between the aligned and unsupported blank edgesand said magnet means for fanning out the blanks at the bottom of thestack, said air gap being smallest at the bottom to provide a maximumflux density in the lowermost blank for accurately positioning it forremoval from the bottom of the stack.

8. In a feeding mechanism for flat sheet metal blanks, the combinationof a magazine having oppositely disposed guides for maintaining blanksin stacked formation between them, said guides on one side of saidmagazine having bottom support means for supporting a plurality of theblanks at the bottom of the stack along one edge, said guides on theopposite side of the magazine being undercut for the free passage of theadiacent unsupported edges of the blanks at the bottom of the stack, andan electro-magnet arranged adjacent the undercut guides for fanning outthe unsupported edges of the blanks at the bottom REFERENCES CITED Thefollowing references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 963,170 Parker July 5, 19101,218,034 Young Mar. 6, 1917 1,716,602 Ross June 11, 1929 1,496,726Myhrum June 3, 1924 Mathiesen Feb. 15, 1944

